#include<iostream>
#include <iomanip>
using namespace std;

int main()
{
	double a,b;
	char x;
	while(1)
	{
		cout << "请输入第一个数字"<< endl;
        cin >> a;
		cout << "请输入第二个数字" << endl;
		cin >> b;
		cout << "请输入运算符" << endl;
		cin >> x;
		if (x == '+')
		{
			cout << setiosflags(ios::fixed);
			cout.precision(2);  
			cout << "result="<<a + b <<endl;
		}
		else if (x == '-')
		{
			cout << setiosflags(ios::fixed);
			cout.precision(2);  
			cout << "result="<<a - b <<endl;
		}
		else if (x == '*')
		{
			cout << setiosflags(ios::fixed);
			cout.precision(2);   
			cout << "result="<<a * b << endl;
		}
		else if (x == '/' )
		{
			cout << setiosflags(ios::fixed);
			cout.precision(2);  
			cout << "result="<<a / b << endl;
		}
	}
	return 0;
}